Standard planetary mass

A Standard Planetary Mass (spm) also known as a Terrestrial Mass was a comparative unit of measurement, used to measure the masses of planets and similar sized objects.

The value of this measurement represented the average mass of a terrestrial planet on which life (and therefore civilization) developed. Most habitable and inhabited planets were close to this size, and this size of planet was most commonly found to be suitable for life and for settlement; without the need for airlocks to maintain breathable atmosphere, shielding against radiation or traherism to generate artificial gravity.

The value of the measurement was based on the mass of Coruscant.

Value
One ssm was equivalent to around 0.000003 standard stellar masses (ssm) or 6,000,000,000,000,000,000,000 (6x10^21, six sextillion) tonnes.

Examples
Coruscant, Muunilist, Neimoidia, Naboo, Alderaan, Mandalore, Kashyyyk, Kamino, Fondor, Endor, Tatooine, Nal Hutta, Hoth, Dantooine, Yavin 4, Dagobah, Utapau, Korriban, Geonosis, and Vitea are all examples of inhabited planets with masses very close to one standard planetary mass.

Some other inhabited planets, however, such as Bespin, Yavia, Tirinos, Nemtox and Polis Massa had masses in excess of or lower than Terrestrial Mass.